High-Voltage Instrument Transformers
！Customization of Various Types of Transformers
Explanation of the Meaning of the Name
Current Transformer
LZZBJ9-10B2
L-Current transformer
Z-Post type
Z-Epoxy Resin Casting
B-With protection class
J-Reinforced type
9-Design No.
10-Rated voltage，kV
B2-Structure code
Voltage Transformer
JDZX10-10R
J-Voltage Transformer
D-Single-phase
Z-Epoxy Resin Casting
X-Winding with residual voltage
10-Design No.
10-Rated voltage，kV
R-With fuse protection
10kV-15kV Current Transformer
Rated Primary Current:5A-5000A；Rated secondary current:5A，1A；Accuracy Class：0.5，0.2，0.5S，0.2S；Protection Class：5P，10P
20kV-35kV Current Transformer
Rated Primary Current:5A-2000A；Rated secondary current:5A，1A；Accuracy Class：0.5，0.2，0.5S，0.2S；Protection Class：5P，10P
3kV-10kV Voltage Transformer
Primary Voltage:3kV-10kV；Rated secondary Voltage:100V，110V，120V，100/3；Accuracy Class：0.5，0.2；Protection Class：3P，6P.
20kV-35kV Voltage Transformer
Primary Voltage:20kV-30kV；Rated secondary Voltage:100V，110V，120V，100/3；Accuracy Class：0.5，0.2；Protection Class：3P，6P.
Combined Instrument Transformers
Primary Voltage:3kV-35kV；Rated Primary Current:5A-1000A；Rated secondary Voltage:100V；Rated secondary current:5A，1A；Accuracy Class：0.5，0.2，0.5S，0.2S；
Zero-sequence current transformer
About Us
JEGO is a technology-driven enterprise specializing in the independent research, development, design, production, and sales of various advanced current and voltage transformers, composite transformers, and transformers featuring deep integration of primary and secondary circuits. The company is headquartered in Wenzhou, known as the “Electrical Capital of China.” Its main products include indoor and outdoor current and voltage transformers, composite transformers, and power metering cabinets in various models ranging from 10 kV to 35 kV.
We operate vacuum-casting production lines using epoxy resin and die-casting production lines; our facilities are equipped with state-of-the-art calibration and testing equipment, including intelligent transformer calibrators and partial discharge testers. We boast a team of experienced senior technical personnel and a comprehensive automated testing process. Our products feature high accuracy, stable performance, safety and reliability, and an aesthetically pleasing design.
We are committed to providing high-quality products and satisfactory service to our domestic and international customers, and look forward to growing together with our clients.
Why Choose Us
Our team is highly cohesive and works in close collaboration to strive for common goals.We stand united and collaborate as one cohesive team.
With advanced design ideas and high-efficiency R&D capabilities, we provide professional and rapid customized design services for electrical equipment.
We apply quality standards superior to market benchmarks and take product quality as the cornerstone of our long-term development.
We are fully customer-oriented, deliver high-quality full-process services and create tailored comprehensive solutions for clients.
Solutions
10-35kV Instrument Transformers: The Precision Sensing and Protection Core for Medium‑Voltage Distribution Networks
In 10–35 kV neutral‑unearthed or arc‑suppression‑coil‑grounded systems, current transformers (CTs), voltage transformers (VTs) – also known as potential transformers (PTs) – and combined transformer units form the “neural terminals” for metering, measurement, and protective relaying. Their performance directly impacts grid safety and economic operation.
Current Transformers (CTs) provide accurate transformation of primary currents. Epoxy‑resin cast column‑type or feed‑through designs are widely deployed in switchgear, ring‑main units, compact substations, and cable branch boxes. Protection‑grade CTs require 5P or 10P accuracy classes with transient anti‑saturation capability, ensuring reliable operation of overcurrent, differential, and other protections under fault conditions. Metering CTs demand 0.2S class to maintain high precision across a broad load range, even at very low currents.
Voltage Transformers (VTs/PTs) are essential for voltage monitoring, synchronisation, and earth‑fault detection. Electromagnetic types are designed with anti‑ferroresonance features and are typically installed on busbars and feeders. Capacitive VTs are commonly used in outdoor AIS substations and can also couple power‑line carrier communication signals. Secondary windings provide metering (0.2 class) and protection (3P class) outputs, while the residual‑voltage winding enables insulation monitoring and supplies signals for earth‑fault selection in small‑current grounded systems. In renewable‑energy grid‑connection scenarios, VTs must support wide‑frequency response and harmonic measurement.
Combined Transformer Units (Metering Units) integrate CT and VT functions in a single enclosure, often using V‑V connection. They are widely applied on outdoor pole‑mounted switches, rural distribution substations, and industrial plant power distribution. These units feature 0.2S‑class metering accuracy and 10P10 protection capability, with fully sealed structures that resist condensation and tampering, while operating reliably in harsh temperature environments. Intelligent combined transformers can incorporate digital interfaces for direct connection to DTUs, facilitating distribution automation upgrades.
In summary, 10–35 kV instrument transformers deliver reliable primary‑side electrical information, serving as the cornerstone for accurate metering, fast protection, and intelligent operation and maintenance of medium‑voltage power networks. For robust, field‑proven solutions that meet the most demanding grid requirements, choose our comprehensive range of CTs, VTs, and combined units – engineered to enhance your grid’s reliability and efficiency.
Contact Us
We hope to become your partner and help your business. We can provide customized services if needed; please contact us.
Business Director: Erick Wang
Email：wang@meinna.com
WhatsApp:+8613336970780